Apparatus for the treatment of ores.



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l Patented July 11,1911.

APPLIGATIOH' FILED SEPT. 7, 1910.

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G. MITCHELL. APPARATUS FOR THE TREATMENT OF ORES.

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APPARATUS FOR THE TREATMENT OF ORES.

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GEORGE MITCHELL, OF LOS ANGELES, CALIFORNIA.

APPARATUS FOR THE TREATMENT OF ORES.

Specification of Letters Patent.

Patented July 11, 1911.

Application filed September 7, 1910. Serial No. 580,796.

To all whom "it may concern:

Be it known that I, GEORGE MITCHELL, of Los Angeles, in the county ofLos Angeles and State of California, have invented certain new anduseful Improvements in Apparatus for the Treatment of Ores; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

My invention relates to an improvement in process and apparatus for thetreatment of ores, and particularly copper, iron, lead, zinc, cobalt,nickel, gold and silver ores.

The object of the invention is to provide means whereby the ore, say forinstance copper, may be smelted, and the matte reduced or bessemerizedor converted in one heat, and by a single continuous operation.

My invention consists broadly in combining with a furnace a series ofhearths and a series of converter chambers located intermediate thehearths, whereby the matte and slag, formed by the smelting, gravitatesor In the accompanying drawings, Figure 1 is a view in verticallongitudinal section of a furnace showing one embodiment of myinvention. Fig. 2 is a view in horizontal longitudinal sect-ion. Fig. 3is a view in transverse vertical section on the line C C, of Fig. 1;Fig. 4 is a similar section on the line A A of Fig. 1. Fig. 5 is a viewin horizontal section of the furnace shown in Fig. 6. Fig. 6 is a viewsimilar to Fig.1 showing converters with removablebottoms mounted ontrucks, and also showing oil burners over the grates. Fig. 7 is a viewin vertical longitudinal section of a portion of a furnace adapted toburn oil only. Fig. 8 is a View in longitudinal vertical section of aportion of a furnace embodying another modification, and Fig. 9 is aview in horizontal section of same.

1 represents a furnace having a cross sectional area substantially asshown in Fig. 1,

and of a length suflicient to provide ample smelting hearths 3, and forthe converters 2,

which as shown are located intermediate the hearths- This furnace isprovided at one end with a fire box 4, which opens directly above thebridge wall 5 into the furnace, and preferably at its other end adjacentthe stack with a steam generator or boiler 5, which utilizes portions ofthe waste heat for generating the steam employed for actuating theblower for the converters.

In the construction disclosed in Fig. 1, I have shown three converters 2formed as an integral part'of the furnace structure, with the twohearths 3 on opposite sides of the converter nearest the fire boxpitched so as to discharge the matte into said converter, and each ofthe other converters with a hearth 3 to the rear, and pitched toward thefront so as to discharge the matte into the converter in advance of thehearth.

I would have it understood that I do not confine myself to anyparticular number of converters. I may use one, but I prefer aplurality, and I may provide a single smelting hearth for each, or mayslope the hearths that each converter will be supplied with matte fromboth sides.

Each converting chamber 2 is provided with twyers 4c and twyer box 6,for the transmission of the blast from a blowing engine, and tunnels 7,are provided at'each side of each converter for the convenience of theoperators in examining the converting chambers and twyers, and toprovide space for the manipulation of tools through the twyers forremoving accretions that form inside of the twyer openings.

The converters as shown, are sunken below the hearths, thereby providinga space the full depth of the furnace above the converters, whichgreatly minimize the wear and tear on the roof, caused by mechanicalaction and the chemical reaction of the matte during the converteroperation.

In the construction shown in Fig. 1 the several converters are of thesame depth and located with the top of one nearer the stack in a higherplane than the one next thereto and so on throughout the series, so thatthe converters may be tapped and the product flow by gravity through asuitable trough into the converter next in advance. With a series ofthese converters such as I have shown, the treatment in the secondconverter would produce what is known as white metal, while thetreatment in the third converter would convert the white metal intometallic copper.

lVith the construction as shown, or with the converters all in the samehorizontal plane, the matte may after treatment in the converter nearestthe stack, be drawn off through a tap hole 9 near the bottom of theconverter, into a ladle, and conveyed by means of a crane to theconverter next in advance, and discharged into the latter through asuitable spout at the side, or through the openings 10 in the top of thefurnace, and after treatment in the second converter, be conveyed to thethird converter and so on throughout the series, if more than three beused. If used as above described, I prefer to place the ore on thehearth supplying the first converter, so that the other converters ofthe series will contain nothing but the partly refined metal.

Instead however of using the converters in sequence as above explained,all of the converters may be operated on what is known as the firststage of converting copper matte, each taking the matte from its hearthor hearths, and reducing it to the point of elimination of nearly allthe iron contents; after which it is drawn off and finished or thereduction completed in another furnace. By this latter operation therewould be obtained the greatest possible amount of heat for smelting, asit is from the first stage of the converting operation that the greatestamount of heat is developed.

In addition to the fire box a at the end of the furnace I have providedthe fire boxes 10 at the side as shown in Fig. 2, which may beadvantageously used at the commencement of the smelting operation. Afterthe smelting has progressed up to the point where there is a sufiicientcharge in one or more of the converters, to blow, the heat generated inthe converters alone will in many instances be ample for smeltingpurposes. If desired the furnace may be started from matte obtained froman auxiliary furnace and thus dispense altogether with the use ofcarbonaceous fuel in starting the smelting. Each converter chamber isprovided near its top with a slag tap 10 through which the slag may beremoved, and each may be constructed with an acid or basic lining orboth as may be desired.

In the construction shown in Figs. 5 and 6, I have provided inlets 12for oil burners in the fire box, and also openings 13 at the side foroil burners 14. V I have also shown the converters with curved, insteadof fiat bottoms, and provided them with removable bottoms 2 mounted incradles 14, carried on trucks 16, the wheels of which run on trackways16, the cradles being supported on hydraulic jacks 18, by which theremovable section of the converter may be raised into position andlowered for its removal to a point where it can be conveniently relined.WVith this latter construction when a removable bottom 2 has beenremoved for repair or relining, another can be run into place, thussaving the time required to repair or reline the removed section. Inthis form of furnace I have also shown bridge walls 19 provided with tapholes 20 arranged conveniently with relation to the sides, so that clayplugs may be placed in the taps or removed therefrom as desired. Thebridge walls form dams for the storage of the matte, during the blowingoperation, hence making the feeding of the matte to the convertersintermittent instead of continuous, as in the other form. By removingthe clay plugs, the matte will be free to run into the converters as itis desired. \Vith the construction comprising bridge walls, I providedoors through which skimming tools may be operated for removing the slagmade by the smelting of the ores. These skimming doors may be arrangedin the side walls of the furnace, or may be carried by any of the doorsin the sides of the furnace opposite the hearths.

In the construction shown in Fig. 7, I have dispensed altogether withthe fire boxes and show oil burners 14 at the end and sides. In thisconstruction I show two converters with twyers and twyer boxes on bothsides.

In the construction shown in Figs. 8 and 9 I have arranged twoconverters side by side without an intervening hearth, the twoconverters, and the larger one also shown, being mounted on trucks aspreviously explained, so as to be moved sidewise for renewal or repair.With these furnaces the ores can be charged onto the hearths throughopenings in the roof of the furnace, and as explained, are smelted bythe heat generated from burning carbonaceous fuel. After sufficient ofthe matte has been liberated and deposited in a converter or converters,the

air blasts are started and the heat generated thereby then smelts orassists in smelting the remaining ores. It will therefore be seen thatby my improvement I smelt the ores and refine the matte by a continuousoperation, thus doing with one apparatus the work generally performed byseparate processes thereby saving in numerous respects the cost ofproducing refined metal. The converter chamber may, if necessary, beinitially heated by fuel oil introduced through burners or through thetwyers or by coal introduced through suitable openings in the furnaceinto the converter chambers.

It is evident that many slight changes might be resorted to in therelative arrangement of parts shown and described without departing fromthe spirit and scope of my invention hence I would have it understoodthat I do not wish to confine myself to the exact construction andarrangement of parts shown and described, but,

I-Iaving fully described my invention what I claim as new and desire tosecure by Letters-Patent, is

1. In a combined smelting and converting furnace, the combination of afurnace chamber, a series of hearths therein, and a converter for eachhearth, the converters located in position to receive the matte bygravity from their respective hearths.-

2. In a combined smelting and converting furnace, the combination of ahorizontal furnace chamber having a series of hearths, and a converterintermediate two hearths and adapted to receive the matte by gravityfrom both hearths.

3. In a combined smelting and converting furnace, the combination of anelongated furnace chamber, having a series of converters and a hearthfor each converterthe said hearths each sloping toward its respectiveconverter so as to discharge matte therein by gravity. 7

4. In a combined smelting and converting furnace, the combination of anelongated furnace chamber, the floor of which is divided up into aseries of hearths, and converters intermediate the hearths, theconverters being so located with relation to the hearths as to receivethe matte by gravity therefrom.

5. In a combined smelting and converting furnace, the combination of anelongated furnace chamber the floor of which is divided into a series ofhearths, and converters, the lower section of each converter beingindependent of the upper section and mounted on a.truck whereby it maybe removed, the series of converters being so located with relation tothe hearths as to receive the matte by gravity therefrom.

6. In a combined smelting and convertin furnace, the combination of anelongated furnace chamber the floor of which forms a hearth and theupper section of a converter, the lower section of the converter beingremovable.

7. In a combined smelting and converting furnace, the combination of afurnace chamber, a series of hearths therein and a series of convertersso located with relation to the hearths as to receive the matte bygravity therefrom, the lower section of each converter being removable.

8. In a combined smelting and converting furnace, a furnace chamber thefloor of which forms a series of hearths and the upper portion of aseries of converters, the lower portions of the converters being mountedon trucks.

9. In a combined smelting and converting furnace, the combination of anelongated furnace chamber having a series of hearths and convertersalternately arranged lengthwise the furnace, the converters being solocated with relation to the hearths as to receive the matte by gravitytherefrom, a fuel burner at one end of the chamber and a stack at theother end.

10. In a combined smelting and converting furnace, the combination of afurnace chamber, the floor of which forms a hearth and the upper sectionof a converter, the lower section of the converter being independent ofthe upper section and mounted on a truck, a fuel burner adjacent one endof said furnace chamber and a stack at the opposite end.

11. In a combined smelting and converting furnace, the combination of ahorizontal furnace chamber having a series of hearths and a converterfor each hearth, each hearth sloping toward its converter so as todischarge the matte therein by gravity and a bridge wall separating eachhearth from its converter.

12. In a combined smelting and converting furnace, the combination of anelongated furnace chamber, coal and oil burners at one end thereof and astack at the other end, the said furnace having a series of convertersand a hearth for each converter, the said hearths each sloping towardits respective converter so as to discharge the matte therein bygravity.

13. In a combined smelting and converting furnace, the combination of afurnace chamber the floor of the latter having a series of converters, ahearth for each converter, the said hearths each sloping toward itsrespective converter so as to discharge the matte therein by gravity, abridge wall separating each hearth from its converter and tap openingsthrough said bridge walls.

In testimony whereof, I have signed this specification in the presenceof two subscribing witnesses.

GEORGE MITCHELL.

Witnesses:

OTTO WILLIAM STRODEHOFF, JANE MERLE R001).

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. G.

